Several treatments for disease require the removal of blood from a patient, processing the one or more components of the blood, and return of the processed components for a therapeutic effect. Those extracorporeal treatments require systems for safely removing blood from the patient, separating it into components, and returning the blood or blood components to the patient. With the advance of medical sciences, it has become possible to treat a patient's blood in closed-loop processes, returning the patient's own treated blood back to him in one medical treatment. An example of such processes include external treatment methods for diseases in which there is a pathological increase of lymphocytes, such as cutaneous T-cell lymphoma or other diseases affecting white blood cells. In such methods, the patient's blood is irradiated with ultraviolet light in the presence of a chemical or an antibody. Ultraviolet light affects the bonding between the lymphocytes and the chemical or antibody that inhibits the metabolic processes of the lymphocytes.
Photopheresis systems and methods have been proposed and used which involve separation of buffy coat from the blood, addition of a photoactivatable drug, and UV irradiation of the buffy coat before re-infusion to the patient. Extracorporeal photopheresis may be utilized to treat numerous diseases including Graft-versus-Host disease, Rheumatoid Arthritis, Progressive Systematic Sclerosis, Juvenile Onset Diabetes, Inflammatory Bowel Disease and other diseases that are thought to be T-cell or white blood cell mediated, including cancer. Apheresis systems and methods have also been proposed and used which involve separation of blood into various components.
Additionally, apheresis systems and methods have also been proposed and used which involve separation of blood into various components, and also involve systems pumping and valving systems which are difficult to manufacture or operate. Prior photopheresis and apheresis systems and methods usually require batch processes and therefore take several hours to treat a patient or to obtain a sufficient supply of separated blood components. Furthermore, the systems are very complex to manufacture, especially the fluid flow controllers and valving systems.
In known photopheresis systems, a disposable kit is provided that is loaded into a permanent piece of hardware. The disposable kit contain complex tubing that is used to carry blood fluids to and from the various devices included in the kit, such as a centrifuge bowl, an irradiation chamber, and various bags for delivering and/or collecting blood fluids. Known disposable kits often contain a cassette, or other controller mechanism, for controlling the flow of blood fluids throughout the disposable kit and to and from the patient. Disposable kits are used only once and must be replaced or disposed after each treatment session. In performing a treatment process, the kit is connected to patient to form a closed-loop system and the various devices of the disposable kit are loaded into a permanent piece of equipment used to drive blood fluids throughout the disposable kit as necessary. Once loaded, the permanent blood drive system drives the blood fluids through the kit's fluid circuitry.
Known permanent blood driving systems have control decks for receiving the cassette of the disposable cassette. In preparing for a blood treatment process, an operator must properly load the cassette into the deck and load the other devices of the kit into their appropriate positions. It is vital that the cassette be loaded properly and not be able to move during treatment. It is also vital to ensure that the disposable kit being loaded onto the permanent blood driving system is compatible with the blood driving system and capable of carrying out the intended treatment. However, these goals must be balanced with the competing goals of reducing the complexity of cassette clamping mechanisms so as to reduce operator loading errors and reducing kit loading time.
Another very real advancement in photopheresis systems would result if the size, manufacturing complexity, manufacturing costs, and tubing within the disposable kit could be reduced, even at the cost of a more complex blood driving system. This is because the blood driving system represents permanent reusable equipment, whereas a new sterile disposable kit must be used each time. Known disposable photopheresis kits are difficult and expensive to manufacture, especially the valving and pumping mechanisms within the cassette.
The size of existing permanent blood driving systems is another issue. Known blood driving systems are bulky and have a very large footprint, taking up valuable hospital floor space. Thus, the above goals must be achieved while maintaining, preferably reducing, the footprint of the permanent blood driving system.
Another deficiency in existing blood driving systems is their inability to communicate or receive real time data during a treatment. If a problem arises during the treatment, either the problem will not be detected and/or nothing can be done until after the treatment. Thus, a need exists for a blood driving system that can both communicate real time data during a treatment and respond if necessary to data inputs in real time during a treatment process.
Additionally, prior photopheresis and apheresis systems and methods usually require batch processes and therefore take several hours to treat a patient or to obtain a sufficient supply of separated blood fragments. It is a constant object to reduce the time it takes to perform a complete photopheresis or apheresis treatment session. Another object is to reduce the amount of blood that must be drawn form a patient and processed in closed-loop processes per photopheresis treatment session. Yet another object to increase the amount of white blood cell yield or obtain a cleaner cut of buffy coat per volume of whole blood processed. Still another object is to reduce the costs and complexity associated with making the disposable kits used.